One-piece buckle



Feb. 29, 1944; E W WHW; 2,343,113

ONE-PIECE BUCKLE Filed May 1"?. 194s was Patente-cl Feb. 29, 1944 UNITEDPATENT OFFICE ONE-PIECE BUCKLE raul w. White, rbrt Lauderale, F1a.,assignr yto Parva Products Company, Chicago, Ill., 'a

corporation of Delaware Armenian-May 17,1943, 'sensi No. 487,22*:

ments, in the use of lsharp prongs or -spikes which inevitably tear andinjure the belt or strap, or

in recourse to the well known pivoted prong or slide type two-:piecebuckles.

With the advent of recent metal shortages and restrictions, which makehighly desirable the adoption of substitute materials, such as n'iold-lable plastics and the like, in lieu of metals, thev advantages ofproviding -a Vone-'piece -buckleha've increased immeasurably. At thesame time, .how-

ever, due to the decreased strength of materials of this character, the.problem-s involved'in providing small, flat, one-piece buckles, whichare inexpensive to construct and easy to thread and which will not slipwhen subject'edto tension, in-

volve even greater difliculties. It isnot thought that any entirelysatisfactory constructionhas heretofore been provided, and accordinglyitis a further object of this invention to provide a onepiece plasticbuckle of pleasing appearance which, when applied to `.a strap, does-not cause excessive bulging, which may be inexpensivelsr manufacturedin any desi-red quantities, and which may readily be manipulated topermit ready adjustment and to secure the strap in desii-ed adjustedpositions.

In carrying out the present invention, a combination of features isemployed which co-perates in a novel manner to provide a ruggedconstruction, ease of threading and adjusting, and a high degree ofresistance to slipping. Strength and ruggedness of the one-piece buckleis achieved by providing a ira-me having strong, thick side bars `ofgreater thickness than the strap, and crossbars of vlesser thicknessselectively inset either from the front or the rear surfaces cf the sidebars, so that the strap, when threaded, lies at least partially Withinthe confines of the side bars thereby avoiding 'excessive bulging. Easeof threading is obtained by employing aand Athe strap whichdoesnot'involve complicated or multiple 4in'terw'iriding of the strapthroughthe buckle, so that when tension is released the free end of thestrap may be readily drawn through the slots oi the frame, the bars andslots at the saine time being so arranged and so vshaped that upon ftheapplication of. tension to the strapslipping of ythe strap relative to'the frame isresisted 'by distortion of thev strap in a plurality ofdirecW tions, by "triction'a'l resistance between overlying portions ofthe strap, and 'by clamping a portion o'f the strap against fa broadclz'i'rnpingy surface of the frame.A

For a more completeunder'standing of the invention "reference should nowbe had to the drawing, in which:

` the buckle of Fig. 4 associated with a strap;

Fig. 6 -is a sectional View` taken along the lines 6-6 oi' Fig. 5;

Fig. 7 is a 'perspective view of another one-piece lbuckle embodying thepresent invention ;Jv

Fig. 8 lis a sectional view taken substantially through the center lineof the buckle shown in 'Fig 7 and illustrating the association of thisby intermediate crossbars Il l5, so a-s to detine a plurality ofstrap-receiving slots H5, l'l, and I8,

As shown best in Figs. l and the inner side walls of the end bars l2 andI3 are curved in opposite directions and, as shown best Fig. 3, the rearwalls of the end bars l2 and` I3 are inset simple co-operative relationbetween the bars '55 from the rear surfaces ofthe side bars lll and llcrossbar I4 is provided with a curved side walll :,y

which is spaced from the curved side wall ofthe end bar I2 so as toprovide the elongate arcuate slot I6 extending across the. bucklejrame.:The

front wall of this intermediate' crossbary I4, as

shown in Figs. 1 and 3, is inset from the iront surfaces of the sidebars I and..II and meets the curved side wall of the bar I4'in`a sharpedge.

The second intermediate crossbiar I is spaced fromthe other edge of theintermediate crossbar I4 to provide the slot I'I which is of a widthonly slightly greater than the thickness of the strap with which thebuckle frame is to be associated, and is spaced from the end wall I3 asufficient distance so that the' slot I8 is adapted to re- A ceive'plural thicknesses of the strap. As shown, the front wall of theintermediate crossbar I5 is inset from the front surfaces of the sidebars I0 and I I a distance vsubstantially, equal to the thickness of theystrap and somewhat 'greater than the inset distance ofthe intermediatecrossbar I4.

Although buckles embodying the present invention may be associated withvarious straps or similar articles, and in fact are capable'of universalapplication wherever 4 detachable fastenings are desired, theembodiments of the invention herein shown are intended particularly foruse with belts, or straps such as wrist-watch straps, adapted toencircle a portion' of the body of the wearer. In the drawing, the strapor belt is shown as comprising an attaching portion 2I which constitutesone end of the belt, and an adjusting portion 22 which terminates in a,free end 23. tion 2I is thickened, as shown,A by sewing or otherwisesecuring thereto a strip of material 24 which may be of the samematerial as the belt or strap,mand"the lower wall of the crossbar I4 isnotched out, vas shown, to provide a recess for this thick end portion.Of course, the thick end on the attaching portion 2I'fma`y be formed inany desired manner, as by doubling over the end of the strap' orbysecuring a metal `clip thereto.

To attach the buckle to the strap, it is necessary only to insert thestrap through the slot I1 and pull itentirely therethrough until ,thethick end portion 24 engages `the'notc'h in the crossbar I4 and preventsfurther 'movement of Athestra'p through the slot. The strap may then bepassed over the upper Asurface ofthe crossbar'IS and rearwardly throughthe ywiderslotl I8, Vand after the strap hasbeenpassd around tl'i'egbodyportion of the wearer, the free end 23 may be passed through theourvedslot I6 from the'rear to the front of the buckle and,pulled'therethrough yuntil the strap reacheslthe'desired adjustedvposition. To secure the 'strapin this position, it is necessary onlytopass the free end rearwardly through the wide slot I3 so that itoverliesthe attaching portion2I and extends between this attachinglportion and the'4 rear wall of the end crossbar I3. l

If tension is now applied to the two portions of the strap intherespective directions indicated At its extreme end the attaching por-v.curved rear edge of the end bar I2.

by the arrows 25 and 26, it will be apparent that the adjusting portionof the strap will be tightly clamped between the rear wall of the endcrossbar I3 and the underlying adjusting portion 2l of the strap. vAtthe same time, the two portions of the strap will be pressed tightlyinto frictional engagement with each other and the part of the adjustingportion 22 which passesY through the curved slot' I 6 will bie sharplybent over the curved front edge of the intermediate bar I4 and the Thissharp bending of the strap occurs at the part thereof which istransversely curved by the walls of the slot I6, and 'the resultingdistortion of the strap, v coupled with the frictional forces and theclamping action beneath the end bar I3, insures that the free end of thestrap will not pull through thebuckle frame and in fact prevents anyslipping movement of the adjusting portion 22 relative to the buckleframe.

Upon release of the tension, the buckle may readily be adjusted, sincethe clamping and frictional forces will immediately be released, and the`adjusting portion of the strap may then readily be pulled through thecurved slot I6 to a new adjusted position. The manner in which theattaching portion12l of the strap or belt is Vsecured to' the buckleframe is of particular value in connection with buckles embodying thepresent invention in that it permits the ready interchange ofvariousstraps for use with a single buckle. Plastic materials from whichthe buckle frame may be constructed may be obtained in various colors,and consequently attractive color schemes vmaybe achieved. For example,a brown buckle may be 'I associated ywith either a brown belt or a.White belt, or a combination brown and White belt,va nd it will beapparent that the interchange of the belts may be achieved with aminimum of effort.

' The embodiment of the invention shown in Figs. 4,55; and is inprinciple'similar to the embodiment described above, except for theproportions of the bars and slots and for the manner in whichthejadjusting portion of the strap is attached thereto. In thisembodiment, the side bars 30 and 3l are connected by end bars 32 and 33and intermediate crossbars 34 and 35 to provide a narrow'curved slot 36similar to slot I6 of the previouslydescribed embodiment, a second slot31, and a wide slot 3,8 similar to the'slot I8 of the previousembodiment.

' In this buckle the attaching portion 39 of the strap is secured tothecrossbar 35 by wrapping the end of the strap about the crossbar andsewing it as indicated by the reference numeral 40.

`In order to accommodate conventional belts of the type having snapfasteners on the attaching 'end thereof, the intermediate crossbar 34 isprovided with a notch 4|, as shown best in Fig. 4, for permitting thesnap fastener to pass' between "the crossbars '3 4 and 35 when thebuckle'is atjtached to the belt." In this embodiment of the inventionthe adjusting portion 43 of the belt is 'threaded through' the' frame insubstantially 'the same manner as describedl in connection with Figs. 1,2, and 3, and the clamping and adjusting action-obtained is in al1respects similar. It will benoted, however, that the slots 36 and 38 arespaced more closely than the slots I6 and I8, and consequently whenYstill? belts or straps are employed'a somewhat greater degree ofbulging'at the portion o'f the ystrap which passes over the 'crossbars'34 and 35 may be encountered. As in `the previously describedembodiment, however,

the various crossba'rs are providedwith front and rear Walls inset fromthe v'iront and `rearsurla'c'es of the sidebars, so thatthe adjustingyportion of the belt 'lies 'at least partially within the coniine's ofthe side bars throughout substantially the length or' the buckle frame.

In 'the' embodiment shown lin Figs. 7 and i8, a similar arrangement oflcrossbars, 'end bars and slots is provided in a buckle frame 50, andfor the purpose of securing `the attaching portion A52| of the belt tothe buckle frame, the invtermersliate crossbar `52 is provided with afinger or prong 53 which extends outwardly from the rear surface of thecrossbar '5.2 adjacent the edge thereof. The attaching portion l of thestrap is provided with an aperture 521 adapted to vbe engaged by theprong 53 when the attaching portion is threaded through lthe frame. Asin the previously described embodiments, the 'adjusting portion 55 ofthe belt is threaded through Vthe nar- -r'ow curved slot and the wideslot of the frame so as to overlie the intermediate crossbars andunderlie the sloping clamping surface of the end bar which defines theWide slot, thereby to provide the heretofore described non-slippingcharacteristics of the invention.

In the embodiment of the invention shown 'in Fig. '9, the side bars 6i)and 6| o'f the buckle frame `are connected by end bars 62 and E3 havinginner curved side Walls, and by crossbars 64 and 65 spaced to provideslots corresponding to the slots inthe previously `describedembodiments. It will of vcourse be understood that the various `frontand rear surfaces -of the'crossbars 62,V 6'3, 64, and 55 are inset fromthe front and 'rear surfaces of 'the side 'bars in the same gen# eralmanner as in the previously described embodiments, but in the structureshown in Fig. 9, the lcurved side Wall 6'6 on the cross'bar 64 is notconcentric with the inner curved side Wall of the end crossbar 62 butinstead approaches the end bar at the ends thereof to provide acrescent-shaped slot 'or a slot having tapering ends. With thisconstruction an additional holding vforce is provided, since thev strap,when threaded through a slot of `this character, will be pinched at theend portions of the slotand crimped toward the center of the slot. Ithas been found that the additional holding force provided by thisfurther distortion of the belt in the Vcurved slot is of particularadvantage in connection with fabric belts, although 'it 'may beadvantageously employed with belts of any desired character.

VWhile I have shown particular 'embodiments of my invention, it will beunderstood, of course, that I do not Wish to be limited thereto sincemany modications may be made, and I, therefore, contemplate by theappended claims 'to cover any such modications as fall Within the truespirit and scope of my invention. Y

Having thus described my invention, What I claim and desire to secure byLetters` Patent is:

1. A one-piece buckle for securing a strap in adjusted positionscomprising a frame of molded material having spaced side bars connectedby end and intermediate crossbars spaced to dcne strap-receiving slotstherebetween, the adjacent side Walls of two of said crossbars beingcurved to define an elongate arcuate slot extending across said frame,the fr'ont wall of one of said two crossbars being inset from the frontsurfaces of said side bars and meeting said curved side wall thereof ina sharp edge, the Width of said slot being only slightly greater than'the thickness .of the strap to `vbe 'secured to .permit the strapto befreely 'threaded therethrough and transversely curved vby the opposedcurved walls .of said slot, .said strap when tensioned in "a directionparallel 4to the plane Fof said frame being sharply bent at 'a`transversely curved portion sthere'o'f over said sharp edge, wherebyslipvpage of 'said 'strap under tension relative to said frame isresisted by distortion of said strap in said slot and vover said edge,said strap `extending lacross the `inset front wall of said onecrossb'ar at least 'partially Within the confines of the front ysurfacesof saids'ide bars.

y2. A Aone-piece buckle for securing a strap in adjusted positions'comprising a frame of molded material .having spaced side barsconnected by end :and'interm'ediate crossbars spaced to definestrap-receiving slots therebetween, the adjacent side walls fof two ofsaid crossbars being curved to l"define :an elongate varcuate slotextending across said frame, the iront vWall of one 'of vsaid twocrossb'ars and fthe rear Wall oi the vother ofsai-d 'frame' is resistedby distortion of said strap,

the portions of said strap adjacent slot eX- tending across said 'insetfront andrear walls of said 'two crossba'r's at least partially Withinthe lconfn'res el" the 'front and rear surfaces of said Side bars.

3. A one-piece buckle for securing strap in adjusted positionscomprising; a iframe of molded material having spaced side barsconnected by end and 'intermediate lcrosslflars spaced to definestrap-receiving slots therebetween, the inner side wall 'of one of saidend 'bars and the adjacent side Wall 'o'f an intermediate bar beingcurved to denne an elongate arcuate slot eX- tending across said frame,the front Wall of said vintermediate bar being inset from the irontsurfaces offsaid side bars and meeting said curved wall 'of saidintermediate A'ba-rin a. sharp edge, vthe Width of said 'slot being onlyslightly greater than the thickness of the strap to be secured to permitthe strap to be freely threaded through said slot and transverselycurved bly the Walls thereof, said strap when tensioned in a directionsubstantially parallel to the plane of said framel being sharply bentover 'said edge at a 'transversely curved portion of said strap, Wherebyslippage ol said strap under tension is re sisted by distortion ofsaid'strap in said slot and over said sharp edge,`said strap extendingacross the inset front wall of said intermediate bar at least partiallywithin the confines of the iront surfaces of said side bars.

4. A one-piece buckle for securing a strap in adjusted positionscomprising a. Trani@ of 'molded material having spaced side barsconnected by vend and intermediate crossbars spaced to deiinestrap-receiving slots therebetween, the inner side wall 'of one of saidend bars and the adjacent side Wall of an intermediate bar being curvedto define an elongate arcuate slot extending across said frame, the`iront v'Wall 0f Said intormediate bar and the rear wall of said one endbar being inset from the front and rear surfaces respectively of saidside bars and meeting said respective curvedl side walls in sharp edges,the width of said slot being only slightly greater than the thickness ofthe associated strap to permit the strap to be freely threaded throughsaid slot and transversely curved by the walls thereof, said strap whentensioned in a direction substantially parallel Yto the plane of saidframe being sharply bent at transversely curved portions thereof oversaid sharp edges, whereby slippage of said strap under tension isresisted by distortion of said strap in said slot and over said edges,said strap extending across said inset front and rear walls of saidintermediate and end bars at least partially within the connes of thefront and rear surfaces of said side bars.

5. In combination .with a strap having an attaching portion and anadjusting portion; a onepiece buckle comprising a frame having spacedside bars connected by end and intermediate crossbars spaced to definestrap-receiving slots therebetween; one of said intermediate barsconstituting a strap-attaching bar about which the attaching portion ofsaid strap extends so asto overlie the front wall thereof and extendrearwardly of the adjacent one of said end bars; another intermediatebar and the other end bar having the opposed side walls thereof curvedto define an elongate arcuate slot extending across said frame forreceiving the adjusting portion if said strap; said adjusting portionwhen thread- `d through said buckle passing rearwardly of said other endbar, through said curved slot, in front of said intermediate bars so asto overlie the attaching portion across said attaching bar, and thenbetween said attaching portion and the rear wall of said one end bar;the width of said curved slot being only slightly greater than,

the thickness of said adjusting portion of said strap to permit saidadjusting portion to be freely threaded therethrough and transverselycurved by the opposed curved walls of said slot; said adjusting portionof said strap when tension is@ applied to said strap portions in adirection substantially parallel to the plane of said frame being bentover the curved edges of said slot at transversely curved portions ofsaid strap and being clamped by said attaching portion against said rearwall of said one end bar; whereby Yslippage under tension of saidadjusting portion relative to said frame is resisted by distortion ofsaid adjusting portion in said slot and over the edges thereof and byfrictional clamping eng-age- .front wall and extend rearwardly of theadjacent one of said end bars; another intermediate bar having its frontwall inset from said front surfaces of said side bars less than saidattaching bar; said other intermediate bar and to the other end barhaving the opposed side walls thereof curved to define an elongatearcuate slot extending across said frame for receiving the adjustingportion of said strap; saidy respective front and rear walls of saidother intermediate and end bars meeting said curved side walls in sharpedges; said adjusting portion of said strap when threaded through saidbuckle passing rearwardly of said other end bar, through said curvedslot, in front of said intermediate bars so as to overlie the attachingportion across said attaching bar, and then between said attachingportion and the rear wall of said one end bar; the width of said curvedslot being only slightly greater than the thickness of said adjustingportion of said strap to permit said adjusting portion to be freelythreaded therethrough and transversely curved by the opposed curvedwalls of said slot; said adjusting portion of said strap when tension isapplied to said strap portions in a direction substantially parallel tothe plane of said frame being sharply bent over the curved edges of saidslot at transversely curved portions of said strap, tightly pressedagainst said attaching portion over said attaching bar and clamped bysaid attaching portion against said rear wall of said one end bar;lwhereby slippage under tension of said adjusting portion relative tosaid frame is resisted by distortion of said adjusting portion insaidvslot and over the sharp edges thereof and by frictional engagementwith said attaching portion and clamping engagement with said one endbar.

'7. In combination with a strap having an attaching portion and anadjusting portion; a onepiece buckle comprising a frame having spacedside bars connected by end and intermediate crossbars spaced to definestrap-receiving slots therebetween; said end bars having the rear wallsthereof inset by substantially the thickness of the strap from the rearsurfaces of said side bars: one of said intermediate bars having thefront wall thereof inset by at least the thickness of said strap fromthe front surfaces of said side, bars and constituting a strap-attachingbar about which the attaching portion of said strap extends so as tooverlie said inset front wall and extend rearwardly of the adjacent oneof said end bars; another intermediate bar having its front wall insetfrom said front surfaces of said side bars less than said attaching bar;said other intermediate bar and the other end bar having the opposedside wallsA thereof curved to define an elongate arcuate slot extendingacross said frame for receiving the adjusting portion of said strap;said respective front and rear walls of said other intermediate and endbars meeting said curved side walls in sharp edges; said adjustingportion of said strap when threaded through said buckle passingrearwardly of said other end bar, through said curved slot, in front ofsaid intermediate bars so as to overlie the attaching portion acrosssaid attaching bar and then between said attaching portion and the rearwall of said one end bar; the width of said curved slot being onlyslightly greater than the thickness of said adjusting portion of saidstrap to permit said adjusting portion to be freely threadedtherethrough and transversely curved by the opposed curved walls of saidslot; said adjusting portion of said strap when tension is applied tosaid strap portions in a direction substantially parallel to the planeof said frame being-sharply bent over` the curved edges of said slot attransversely curved portions of said strap, tightly pressed against saidattaching portion over said attaching bar and clamped by said attachingportion against said rear Wall asiat-1s 5 of said one: end bar; wherebyslippage .undertonsion of said adjusting portiony relative tofsaid frameis. resisted bydistortionof said. adjusting portionin said slot and,over `the sharp edges thereof and by frictional engagement withf saidattaching portion andclamping engagement with said one end; bar; saidadjusting portion passing rearwardly of said end bars and said*Iattaching portion passing, in4 front. of saidv attaching bar lyingsubstantially w-ithin the connnes of the front and rear. surfacesv ofsaid sidev bars. v l l 8. In combination withv a, strap having attachingportion and an adjusting portion; a one.- piece buckle comprising atrame having lspaced side bars connected by. end and intermediatecrossbars spaced. to, denne strap-receiving: slots therebetween; one ofsaid intermediate bars constituting; a strap-attaching barabout whichthe attaching portion of said strap extends so as to overlie the frontwall of said bar and extend rearwardly of the adjacent one of said endbars; another intermediate bar and the other end bar having the opposedside walls thereof curved to denne an elongate arcuate slot extendingacross said frame for receiving the adjusting portion of said strap;said adjusting portion when threaded through said buckle passingrearwardly of said Iother end bar, through said lcurved slot, in frontof said intermediate bars so as to overlie the attaching portion acrosssaid attaching bar and then between said attaching portion and the rearwall of said oney end bar; said curved side walls converging adjacentthe side bars of.

said frame whereby the Width of said curved slot gradually decreasesfrom a maximum width only slightly greater than the thickness of saidadjusting portion of said strap; said adjusting portion when threadedthrough said curved slot being pinched at the edges thereof and crowdedtoward the center of said curved slot while being transversely curved bythe opposed curved walls of said slot; said adjusting portion of saidstrap when tension is applied to said strap portions in a directionsubstantially parallel to the plane of said frame being bent over thecurved edges of said slot at transversely curved portions of said strapand being clamped by said attaching portion against said rear wall ofsaid one end bar; whereby slippage under tension of said adjustingportion relative to said-frame is resisted by distortion of saidadjusting portion in said slot and over the edges thereof and byfrictional clamping engagement with said attaching portion and said oneend bar.

9. In combination with a strap having an attaching portion and anadjusting portion; a onepiece buckle comprising a frame having spacedside bars connected by end and intermediate crossbars spaced to dennestrap-receiving slots therebetween; said intermediate bars dening a slottherebetween for receiving said attaching portion of said strap; one ofsaid intermediate bars constituting a strap-attaching bar and having axed prong of a length less than the thickness of said strap extendingfrom a rear wall thereof for engaging a hole in said attaching portionadjacent the end thereof when said attaching portion is threaded throughsaid slot and about said strap-attaching bar so as to overlie the frontwall of said bar and extend rearwardly of the adjacent one of said endbars; another intermediate bar and the other end bar having the opposedside walls thereof curved to define an elongate arcuate slot extendingacross said frame for receiving the adjusting portion of said strap;

said adjusting portion when threaded. through .said buckle passingrearwardly of. said'v other end through and. transversely curved'. bythe opposed curved walls offsaid slot; said adjusting portion of saidstrap when tension is applied to said strap portions ina directionsubstantially parallel' to the planel of said frame being bent over thecurved, edges oi' said slot at transversely curved portions of saidstrap'and being' clamped by said attaching portion lagainst' said rearwall of said one end' bar; whereby slippageunder tension of saidadjusting portion relative to said frame is resisted by distortion ofsaid adjusting portion in said slot and over the edges thereof and byfrictional clamping engagement with said attaching portion and said oneend bar.

10. In combination with a strap having an attaching portion and anadjusting portion, a onepiece buckle comprising a frame havin-g spacedside bars connected by end and intermediate crossbars spaced to dennestrap-receiving slots therebetween; said intermediate bars defining aslot of a width substantially equal to the thickness of said strap, saidattaching portion of said strap having an end of greater thickness forpreventing movement thereof through said slot beyond a predeterminedpoint; one of said intermediate bars constituting a strap-attaching barabout which the attaching portion of said strap adjacent said thick endextends so as to overlie the front wall of said bar and extendrearwardly of the adjacent one of` said end bars; another intermediatebar and the othel` end bar having the opposed side walls thereof curvedto define an elongate arcuate slot. extending across said frame forreceiving the adjusting portion of said strap; said adjusting portionwhen threaded through said buckle passing rearwardly of said other endbar, through said curved slot, in front of said intermediate bars so asto overlie the attaching portion across said attaching bar and thenbetween said attaching portionvand the rear wall of said one end bar;the width of said curved slot being only slightly greater than thethickness ci said adjusting portion of said strap to permit saidadjusting portion to be freely threaded therethrough and transverselycurved by the opposed curved walls of said slot; said adjusting portion'justing portionA relative to said frame is resisted by l distortion ofsaid adjusting portion in said slot and over the edges thereof and byfrictional clamping engagement with said attaching portion and said oneend bar.

11. A one-piece plastic buckle for securing a strap in adjustedpositions comprising a frame having spaced side bars of a thicknessgreater than the thickness of the strap, said side bars being connectedby end and intermediate bars of less thickness than said side bars, saidend bars having oppostely curved inner side walls -and having the rearwalls' thereof inset from the rear surfaces of said side bars, the insetrear wall of one end bar meeting the curved side Wall thereof in a sharpedge to provide a sharp distortion line for the strap, and the insetrear wall of the other end bar gradually merg ing into the curved sidewall thereof to provide a broad clamping surface for the strap, onevintermediate bar having a curved side wall spaced from the inner curvedwall of said one end bar to deine an arcuate slot of .a width onlyslightly greater than the thickness of the strap and having its frontWall inset from the front surface of said s'ideloars and meeting thecurved side wall thereof in a sharp edge, a. second of said'intermediate bars being spaced from said otherv end bar to pro- 'vide aslot of sumcient' width to receive plural thicknesses of said strap,said intermediate bars v having -a'slot therebetween for receiving Aanattaching portion of the strap atleast partially en circling said'secondintermediate bar and passing through said plural thickness slot tounderlie said clamping surface, whereby a strap having its attachingportion secured to and encircling said second intermediate bar andthaving its other end threaded through said curved slot from-the rear ofthe vframe and through said plural thickness slot from the front of theframe over the attaching portion of the strap will when subjected totension be held against slipping relative to the frame bythe distortionof the strap in said curved slot and over said sharp edges and byclamping engagement of the threaded portion of the strap between saidclamping surface and said attaching portion of the strap.

PAUL W. WHITE.

